Power locking/unlocking is a popular feature for vehicle door latches. Typically, power-locking latches are equipped with a DC motor that drives a series of gears and cams to actuate a lock lever between the locked and unlocked position. However, for both safety and convenience purposes, the latch must also be able to be locked and unlocked manually. Preferably, manual locking/unlocking should not back drive the power-locking drive train. Previously, it has been difficult and/or expensive to produce an actuating device that allowed both manual and power locking and unlocking. In addition to power locking/unlocking, other components of the latch are becoming motorized. For example, some latches are now equipped with a power release feature. In a latch equipped with power release, the pawl is typically spring-biased against the ratchet. A DC motor drives the gear train to actuate the pawl into the released position. Once released, the motor must disengage to allow mechanical latching.
One solution is to provide a cam that can actuate the lock lever when the motor is engaged, but remains clear of the lock lever's motion path when the motor is disengaged. In this fashion, the lock lever can be manually actuated without difficulty. However, in practice it has been found that such systems do not always move fully clear of the lock lever's travel path. For example, when a cam is forced to stop rotating, it may bounce back into the path of the lock lever. In this case, the cam may partially or fully hinder manual actuation of the lock lever.
What is desired is an actuating device for a vehicle door latch that provides power locking/unlocking and reliably allows for manual locking/unlocking without manually back driving the drive train. What is also desired is an actuating device for a vehicle door latch that provides power release and allows manual latching. Additionally, the actuating device should be inexpensive to assemble.